/*  the normalize routine converts the raw reading of a photocell sensor  (typically: 10 in bright light; 200 in dark light) into values  appropriate for controlling the motors (0= off; 100= full speed  forward).*/  int normalize(int value){    int bright= 10;    int dark= 200;    int output= 100 - ((value - bright) * 100) / (dark - bright);    if (output < 0) output= 0;    if (output > 100) output= 100;    return output;}